The invention relates to a shaft connecting device for a heald shaft of a weaving machine.
In most cases weaving machines comprise several heald shafts that are embodied by an essentially rectangular frame holding a large number of healds. The heald shafts usually have two shaft rods that are held horizontally during operation, said heald shafts being connected on their ends by vertically oriented lateral supports. These units are moved up and down in vertical direction by a shaft drive.
Such a heald shaft is disclosed, e.g., by document U.S. Pat. No. 6,378,564 B1. In order to move the heald shaft in vertical direction, its two lateral supports are connected on their respective lateral ends to a thrust rod. To do so, the thrust rod is connected to the carriage of a vertical guide. The lateral support of the heald shaft is also connected to the carriage of the vertical guide by means of a suitable hook.
For various reasons heald shafts need to occasionally be removed from the weaving machine and then set back into said machine. To achieve this, the connection between the thrust rod and the lateral support must be separated. This should be possible in the simplest manner and with only a few movements. On the other hand, it must also be possible to reliably re-establish the connection.
Document JP 9-21030 A discloses a heald shaft that comprises lateral supports that can be vertically shifted in a guided manner. On their upper ends, the lateral supports are braced with mounting blocks. The threaded free upper ends of the thrust rods are set into these bracing blocks and screwed with nuts to said blocks. The thrust rods are guided separately and are at a distance from the lateral supports.
A different concept is illustrated by utility model DE 91 03 031 U1. It uses as basis a heald shaft that is moved up and down by means of traction means. The traction means are ropes, for example. A traction means attaches to the upper end of the lateral support for moving and guiding the heald shaft, said traction means being fastened there by means of a clamping device.
Another concept is known from document EP 0 520 540 A1. It discloses heald shafts with hollow lateral supports, in which case a drive rod extends in vertical direction through the inside space of said lateral supports. The thrust rod has on its lower end a screw thread that is screwed to the lateral support. On the upper end of the lateral support an adjusting screw is provided, whereby the end face of said screw abuts against the end face of the thrust rod.
The examined Japanese utility model JP 06-38124 Y2 teaches that a thrust rod be configured in such a manner that it may receive the lateral support of a heald shaft in a positive-locking manner. A clasp with a clamping screw is used to fasten or unfasten the heald shaft. The thrust rod is guided by stationary guides and thus takes over guiding of the heald shaft. A height adjustment of shaft from the top is not possible.
It is the object of the invention to provide a shaft connecting device for a heald shaft of a weaving machine, said connecting device being constructed in a simple manner and for safe handling. In addition, the easiest possible handling is to be made possible.